Zinc plating is a self sacrificing finish, applied to steel to give corrosive resistance and a decorative finish. Sacrificial finishes allow the zinc coating to be attacked by a corrosive element such as moisture, thus protecting the base steel. Chromate conversion coatings can be completed over the zinc in various decorative colors that not only look good but also enhance its protective abilities. The protective nature of zinc plating can be further increased through the application of seals, waxes or lacquers. Zinc can also serve as an excellent primer base for painting by adding corrosive protection without interfering with decorative coloring.
Barrel Zinc — Barrel zinc plating is used to plate small diverse parts. The parts are placed inside a perforated, rotating barrel for an even finish. Coating thickness is controlled by load size, current density applied and duration in the bath. Conversion coatings are applied after the plating process. Many commercial platers process large loads in massive machines that roll the parts over and over on a horizontal axis, leading to potential part damage and bending problems. But not Volunteer Metal Finishing. Our process is designed to handle lighter, more delicate parts in smaller barrels that slowly rotate on a 45° axis. This gives an even finish while minimizing the damage potential from rotation of the parts.
Rack Zinc — Rack zinc plating is used for two very different types of parts. The first are parts that are too delicate for even our small barrels. The second are parts that are too large or heavy to barrel plate. With rack zinc plating, these parts remain stationary on the rack and don’t rotate. All conversion coatings and post coatings are also available on our rack line.
Trivalent chromates are available in clear, yellow and black.
Industry standards recommend that some heat treated or hardened steel parts be pre-baked for stress relief purposes or post-baked to ensure relief of captured hydrogen to prevent embrittlement. Volunteer Metal Finishing offers baking as required to ensure the requirements are met.